The relationship between the magnetic resonance imaging appearance of the lumbar spine and low back pain, age and occupation in males.

The purpose of this study was to undertake a critical review of the potential role of magnetic resonance imaging (MRI) in the evaluation of low back pain (LBP) and to determine if there were differences in the MRI appearances between various occupational groups. The study group, 149 working men (78 aged 20-30 years and 71 aged 31-58 years) from five different occupations (car production workers, ambulance men, office staff, hospital porters and brewery draymen), underwent MRI of the lumbar spine. Thirty-four percent of the subjects had never experienced LBP. Twelve months later, the examination was repeated on 89 men. Age-related differences were seen in the MRI appearances of the lumbar spine. Disc degeneration was most common at L5/S1 and was significantly more prevalent (P < 0.01) in the older age group (52%) than in the younger age group (27%). Although LBP was more prevalent in the older subjects there was no relationship between LBP and disc degeneration. No differences in the MRI appearance of the lumbar spine were observed between the five occupational groups. Overall, 45% had 'abnormal' lumbar spines (evidence of disc degeneration, disc bulging or protrusion, facet hypertrophy, or nerve root compression). There was not a clear relationship between the MRI appearance of the lumbar spine and LBP. Thirty-two percent of asymptomatic subjects had 'abnormal' lumbar spines and 47% of all the subjects who had experienced LBP had 'normal' lumbar spines. During the 12-month follow-up period, 13 subjects experienced LBP for the first time. However, there was no change in the MRI appearances of their lumbar spines that could account for the onset of LBP. Although MRI is an excellent technique for evaluating the lumbar spine, this study shows that it does not provide a suitable pre-employment screening technique capable of identifying those at risk of LBP.

The red cell indices. Yesterday, today, and tomorrow.

The red cell indices of mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration have been standard methods of evaluating anemia since they were developed by Wintrobe in the 1930s. This article discusses the technical variabilities that have rendered the classic red cell indices less useful than was originally claimed for the differential diagnosis of anemia; examines the literature regarding the diagnostic utility of the newer indices; and suggests possible newer indices that may be added to routine hematology analyzers to render the information they generate more clinically useful.

Lumbar muscularity and its relationship with age, occupation and low back pain.

This paper considers an internal standard of lumbar muscularity. The cross-sectional areas (Acs) of the intervertebral disc and paraspinal muscles were measured in 147 working men from an axial magnetic resonance image passing through the L3-4 disc. Lumbar muscularity was expressed by two ratios; the ratio between the Acs of the right psoas and the Acs of the intervertebral disc (P:disc), and the ratio between the combined Acs values of the right erector spinae and quadratus lumborum and the Acs of the disc (ESQL:disc). When the subjects were divided into two age groups (76 aged 20-30 years and 71 aged 31-58 years) lumbar muscularity was found to be significantly greater (P less than 0.001) in the younger age group (P:disc = 0.8, SD 0.2; ESQL:disc = 2.0, SD 0.3) than in the older age group (P:disc = 0.7, SD 0.2; ESQL:disc = 1.8, SD 0.3). Lumbar muscularity was not significantly affected by occupation or by a history of low back pain.

Analytic inaccuracy resulting from hematology specimen characteristics. Three cases of clinically misleading artifacts affecting white blood cell and platelet counts.

Sporadically, hematology analyzers generate grossly erroneous results for one or several parameters of the complete blood count (CBC) because of a characteristic or peculiarity of an individual patient specimen. This article presents three cases of relatively less well-known analytic errors of this sort, falsely elevating white blood cell count and platelet count and decreasing total white blood cell count, as determined on a Coulter Aperture Impedence Analyzer. The type of alteration in the CBC parameters and the instrument histogram abnormalities seen in each of these different types of analytic inaccuracy are discussed.

Massive hemolysis in Clostridium perfringens infections.

Over a 14-month period at the Cleveland Clinic Foundation, 424 strains of Clostridium were isolated; of these, 52 strains were Clostridium perfringens isolated from 41 patients. Eight strains of C. perfringens were isolated from the blood of six patients; five of these patients had neoplastic disease and three developed massive intravascular hemolysis with rapidly developing shock and death. Clinical details are given on three patients with fatal Clostridium perfringens sepsis, and the nature of presentation and pathophysiologic mechanisms are discussed.

Marrow myxedema. Gelatinous transformation of marrow ground substance in a patient with severe hypothyroidism.

Replacement of marrow ground substance by hyaluronic acid-rich mucopolysaccharides (gelatinous transformation) has been previously reported to occur in severely malnourished patients. A patient with severe anemia and hypothyroidism without malnutrition was found to have gelatinous transformation of the marrow. This process is similar histologically to dermal myxedema, and the findings in this patient suggest questions for further study involving possible roles for thyroid-stimulating hormone in the development of marrow and visceral myxedema and the alterations in the normal partitioning process between serum and red blood cell low-density lipoproteins that produce acanthocytes in blood smears from patients with hypothyroidism.

Lymphocyte percentage correlations for the Coulter S+IV.

Previously performed correlation studies involving the Coulter S+II TM demonstrated a statistically significant bias for lymphocyte enumeration as compared with the results of lymphocyte enumeration by an automated differential counting system manufactured by Geometric Data, the Hematrak TM. New data developed utilizing the Coulter S+IV TM indicates that the previous bias has now been eliminated.